package com.aixin.csopservice.utils;

//import org.apache.commons.codec.binary.Base64;
//import org.apache.tomcat.util.codec.binary.Base64;
import org.apache.commons.codec.binary.Base64;

import javax.crypto.Cipher;
import java.security.*;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;

public class RSA2Util {

    private static Map<Integer, String> keyMap = new HashMap<Integer, String>();  //用于封装随机产生的公钥与私钥

    private  static String publickey  ="MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC/sOMRawzPybNCNIaT07SCLlOOFriyFwvpiTF+D+IZx6PQQ9KxXH4tVOUPZfj2UDcsMUdiFamHYY+OmLTO4bcJelBfIWXh5/KXGP9D/Vw7M1NmX8Iy3DPsNkkbihhxiwHoipsPCQ6Ph9kZ8+LqIiwQpLCjqSBXo0v/Dza3tzVtAQIDAQAB";

    private static  String privateKey ="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";

    public static void main(String[] args) throws Exception {
        //加密字符串
        String message = "123456";
        String messageEn = encrypt(message);
        System.out.println(message + "\t加密后的字符串为:" + messageEn);
        String messageDe = decrypt(messageEn,privateKey);
        System.out.println("还原后的字符串为:" + messageDe);
    }

    /**
     * 随机生成密钥对
     * @throws NoSuchAlgorithmException
     */
    public static void genKeyPair() throws NoSuchAlgorithmException {
        // KeyPairGenerator类用于生成公钥和私钥对，基于RSA算法生成对象
        KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");
        // 初始化密钥对生成器，密钥大小为96-1024位
        keyPairGen.initialize(1024,new SecureRandom());
        // 生成一个密钥对，保存在keyPair中
        KeyPair keyPair = keyPairGen.generateKeyPair();
        RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();   // 得到私钥
        RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();  // 得到公钥
        String publicKeyString = new String(Base64.encodeBase64(publicKey.getEncoded()));
        // 得到私钥字符串
        String privateKeyString = new String(Base64.encodeBase64((privateKey.getEncoded())));
        // 将公钥和私钥保存到Map
        keyMap.put(0,publicKeyString);  //0表示公钥
        keyMap.put(1,privateKeyString);  //1表示私钥
    }
    /**
     * RSA公钥加密
     *
     * @param str
     *            加密字符串
     *            公钥
     * @return 密文
     * @throws Exception
     *             加密过程中的异常信息
     */
    public static String encrypt( String str) throws Exception{
        //base64编码的公钥
        byte[] decoded = Base64.decodeBase64(publickey);
        RSAPublicKey pubKey = (RSAPublicKey) KeyFactory.getInstance("RSA").generatePublic(new X509EncodedKeySpec(decoded));
        //RSA加密
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.ENCRYPT_MODE, pubKey);
        String outStr = Base64.encodeBase64String(cipher.doFinal(str.getBytes("UTF-8")));
        return outStr;
    }

    /**
     * RSA私钥解密
     *
     * @param str
     *            加密字符串
     * @param privateKey
     *            私钥
     * @return 铭文
     * @throws Exception
     *             解密过程中的异常信息
     */
    public static String decrypt(String str, String privateKey) throws Exception{
        //64位解码加密后的字符串
        byte[] inputByte = Base64.decodeBase64(str.getBytes("UTF-8"));
        //base64编码的私钥
        byte[] decoded = Base64.decodeBase64(privateKey);
        RSAPrivateKey priKey = (RSAPrivateKey) KeyFactory.getInstance("RSA").generatePrivate(new PKCS8EncodedKeySpec(decoded));
        //RSA解密
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.DECRYPT_MODE, priKey);
        String outStr = new String(cipher.doFinal(inputByte));
        return outStr;
    }

}

